NYU Hospital for Joint Diseases, New York, NYMemorial Sloan-Kettering Cancer Center, The Lucille Castori Center for Microbes, Inflammation and Cancer, New York, NYNYU College of Dentistry, New York, NYNYU School of Medicine, New York, NY

Background/Purpose:

To profile the subgingival oral microbiota abundance and diversity in patients with new-onset, never-treated rheumatoid arthritis (NORA), in comparison with chronic-established RA (CERA), and healthy individuals.

Methods:

Periodontal status, clinical activity and sociodemographic factors were determined in patients with NORA (n=25), CERA (n=27), and healthy subjects (n=14). All RA patients enrolled in the study were ACPA positive. Dental examinations and biofilm acquisitions were performed by three calibrated and qualified periodontists in the NYU Rheumatoid Arthritis Periodontal Disease (RAPD) clinic. Massively parallel-454 pyrosequencing technologies were used to compare the composition of microbial communities in subgingival biofilms and establish correlations between presence/abundance of bacteria and disease phenotypes.

Results:

The severe forms of periodontal disease were found in 75% percent of NORA patients, higher than that observed in CERA (57%), and healthy controls (8%) (p <0.01, all RA vs healthy controls; see Table). The oral microbiome of RA patients was equally dense and diverse compared to controls. However, the microbiome of patients with NORA was distinct, characterized by several bacterial families and genera that are more prevalent and abundant than observed in CERA), or healthy controls. Specifically, red-complex bacteria, the most virulent periodontopathic organisms, are overabundant in NORA, and decrease in better-controlled, treated RA (CERA). A single species-level operational taxonomic unit (OTU) belonging to the genus Porphyromonas and homologous to P. gingivalis is significantly more prevalent and abundant in NORA patients than in CERA or healthy subjects (p<0.05) (Figure).

Table. Prevalence and severity of periodontal disease in healthy individuals and patients with NORA or CERA

Severity of Periodontal Disease

Group

Healthy Gums

Gingivitis

Slight

Moderate

Severe

Healthy controls (n=14)

62%

15%

0

15%

8%

NORA (n=25)

0

4%

4%

17%

75%

CERA (n=27)

0

10%

10%

23%

57%

p value (ANOVA)

p <0.01

NS

NS

NS

p <0.001

Conclusion:

Moderate to severe periodontal disease is present in over 90% of patients with new onset RA. Our data indicate that the oral microbiome of these drug-naïve, ACPA + NORA patients is distinct at disease onset, characterized by the overabundance of a single and virulent Porphyromonas species. These studies suggest that the further identification and characterization of a particular Porphyromonas species may explain the reported link between RA and periodontal disease.